[S390] dasd: provide a Sense Path Group ID ioctl

The BIODASDSNID ioctl executes a 'Sense Path Group ID'
command on a DASD ECKD device. The returned path group data
allows user space programs to determine path state and
path group ID of the channel paths to the device.

Signed-off-by: Stefan Weinhuber <wein@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

1 files changed, 22 insertions, 18 deletions

diff --git a/arch/s390/include/asm/dasd.h b/arch/s390/include/asm/dasd.h
index 218bce81ec70..b604a9186f8e 100644
--- a/arch/s390/include/asm/dasd.h
+++ b/arch/s390/include/asm/dasd.h
@@ -217,6 +217,25 @@ typedef struct dasd_symmio_parms {
         int rssd_result_len;
 } __attribute__ ((packed)) dasd_symmio_parms_t;
 
+/*
+ * Data returned by Sense Path Group ID (SNID)
+ */
+struct dasd_snid_data {
+        struct {
+                __u8 group:2;
+                __u8 reserve:2;
+                __u8 mode:1;
+                __u8 res:3;
+        } __attribute__ ((packed)) path_state;
+        __u8 pgid[11];
+} __attribute__ ((packed));
+
+struct dasd_snid_ioctl_data {
+        struct dasd_snid_data data;
+        __u8 path_mask;
+} __attribute__ ((packed));
+
+
 /********************************************************************************
  * SECTION: Definition of IOCTLs
  *
@@ -261,25 +280,10 @@ typedef struct dasd_symmio_parms {
 /* Set Attributes (cache operations) */
 #define BIODASDSATTR   _IOW(DASD_IOCTL_LETTER,2,attrib_data_t) 
 
+/* Get Sense Path Group ID (SNID) data */
+#define BIODASDSNID    _IOWR(DASD_IOCTL_LETTER, 1, struct dasd_snid_ioctl_data)
+
 #define BIODASDSYMMIO  _IOWR(DASD_IOCTL_LETTER, 240, dasd_symmio_parms_t)
 
 #endif                          /* DASD_H */
 
-/*
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- * End:
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